Electric-lamp socket.



V. E. EXTROM & C. H. GRUNDY.

ELECTRIC LAMP SOCKET.

APPLICATION FILED 0CT.9, 1907.

Patented Jan. 19, 1909.-

I N VE N T0196 7 0502122. Extra) 6 kaJz. 6522472679 W/TNESSES/ A TTOHNE VS 'UNITEED STATES PATENT OFFICE. I

VIOTGR E. EXlROM AND CHARLES HANCOCK GRUNDY, OF TOMAHAWK, WISCl'JNSIN.

ELECTRIC-LAMP SOCKET.

Specification of Letters Patent.

Patented Tan. 19, 1909.

Application filed October 9, 1907. Serial No. 396,624.

To all whom it may concern:

Be it known that we, VICTOR E. EXTROM and CHARLES HANCOCK GRUNDY, both citizens of the United States, and residents of Tomahawk, in the county of Lincoln and- State of Wisconsin, have invented a new and Improved Electric-Lamp Socket, of which the following is a full, clear, and exact description.

The purpose of this in vention is to provide novel, simple details of construction for an electric lamp socket, which will serve to control the flow of current to two lamps by the turnin movement of a single key, and thus eii'ect t 1e lighting of either one of two lamps, light both lampssimultaneously, or extinguish them together or successively as may be desired.

The invention consists in the novel construction and combination of parts, as is hereinafter described and defined in the appended claims.

Reference is to be had to the accompanying drawin forming a part of this s ecification, in whic similar characters of re erence indicate corresponding parts in all the views.

' l i ure 1 is a perspective view, showing two e ectric lamps connected by means of the improvement; Fig. 2 is an enlarged partly sectional side view, showin the interior construction of the improve socket, having parts thereof adjusted for cutting otf electric connection from two lamps that are directly connected therewith; Fig. 3 is a partly sectional side view of the improved socket, showing details therein adjusted for lighting a single lamp; Fig. i is a side view of the improved socket, broken away, showing in-' terl'or pa-rts adjusted for lighting two lamps at the'sanietimaand Fig. 5 is a sectional pla'n'view of the improved socket, substantially on the line 5-5 in Fig. 2.

It has been found of cat practical ad vantage to enable the quick andconvenient control of a lamp pendent from a ceiling or on a side bracket, and another lamp on a movable stand, by manipulation of a single key which is carried by a socketon one of the lamps. f

In cariying into effect the principle of our invention, one embodiment is shown and comprises the'followin details: A socket body 5 that is mainly cyl formed of plate metal to avoid excessive ;weight,'is contracted in diameter at or near its normally lower end, thus producmg a holindrical and maybe low branch 5 thereon. At one side of the body 5, a lateral hollow branch 5' is formed or secured. The body and its branches are lined with insulating material that forms a continuous wall therein.

Within the portions of the lining 6 that extend into the branches 5*, 5 metallic sleeves or linings 7 are inserted. The linin walls 7 are internally threaded and said threads may be indented into the insulating wall 6, these threads being quite coarse to adapt them for the engagement therein of parts that will presently be described.

Upon the upper end of the body 5, a cap piece 5 is fitted and. secured detachably, it having a central opening 12 therein that permits the insertion of positive and negative electric conductor wires 0, 0, within the body of the socket. The wires 0, a, are insulated from each other, and one wire 0, is firmly secured at its end upon an upwardly extended strip 0 that is on the lining shell 7 which occupies the insulation 6 in the lateral branch 5', as shown in Fig. 2.

Two resilient metallic strips 03, d, are lapped together attheir upper ends and secured by suitable means on the insulating wall 6, preferably at a point directly opposite the branch 5", and upon the upper extremities of the connected strips 03, d the depending end of the conductor wire 0 is secured and adapted for transmission of current through said strips from a source of electricity, when a closed circuit is established, as will hereinafter appear.

A coupling head 8, formed of plate meta or other available material, is provided witha cylindrical shank 8 at one end, and said shank is exteriorly threaded and screwed into the thread in the metal lining 7 of the branch 5*, as shown in Fig. 2.

Two insulated conductor wires e, e, are located in the coupling head 8, one wire 6,

being attached to the wall thereof, while the other wire 6', extends through the shank 8 and terminates in a resilient contact strip 0 that is preferably bent laterally as shown in the drawings, to give it V-shape and thus adapt it for resilient action as a contact The strip d is bent at d, so as to project it toward the shank 8' and then double folded as shown at d from which folds a spring contact limb d depends, and is positioned near to and opposite the resilient terminal of the strip 6 on the wire 6. The

in wires g,

conductor strip is extended downward, and near the lower branch of the socket bod 5 is double folded, producin a spring f om which extends a contact imb f toward, but below, the lower end of the contact limb d.

A glass electric light bulb 9, of usual form and terminating at one end in an exteriorly threaded shank 9, is screwed into the internal thread formed in the lining wall 7 for the depending branch 5, and in the shank and glass guard stem 9 that projects therefrom into the bulb 9, two insulated leadingare embedded, and at their terminals, w ich are positioned at the lower end of the guard stem, and ends of a carbon filament 10 are secured in a manner that insures perfect electrical connection therebewith, the limb f.

limbs and the latter will remain in normal tween.

As shown, one wire 9 is bent laterally and at its upper end is embedded in the lining wall 7 for the branch 5. The remaining wire 9 is extended up through the glass shank 9", and at the upper end thereof merges into a resilient contact finger h, that is located directly below but not 1n contact It will be understood from the receding description, and by inspection of t e drawings, that the contact limbs d and f are dis osed in the same vertical plane substantia y at right angles with each other, and out of contact, and furthermore, that said limbs are normally separated slightly from the contact fingers e and h.

A key shaft 2' is su'ported transversely in the body 5 and insu ation 6, by journalin its end portions therein at a point which wil dispose said shaft between and at an equal distance from the limbs 12 and f.

A. fiat grip iece or head i is formed or secured u on t e end of the shaft 5 that projects outside of the body 5, and upon said shaft in the same vertical lane with the limbs al*, a presser block '8 is mounted and secured. The presser block 11 is formed of hard rubber or other non-conductor of electricit and is peripherally rhombus-shaped, the s aft 6 being passed therethrough near one of the obtuse angles m thereof.

It will be seen in Fig.2 that when the shaft 73 is turned so as to locate the obtuse angle m, it is close to, nearest the free ends of the contact limbs d, f, the acute angles of the presser block will be removed from said iplgsition or out of contact with either contact er e, h. I s represented in Fig. 1, the improved socket and depending lamp thereon, is hung by the insulated wires 0, a, from an overhead supiort, such as the ceiling A in a room, an receives current from a suitable source.

The coupling head 8 and wires e, e, that are shown broken away in Fi 2 in complete form extend from the socket branch 5 to a stand lamp 11 of any referred construction, and as will be un erstood, both lamp? Wlll be extinguished when the key bloc i is positioned with regard to the contact limbs d and f, as shown in Fig. 2.

In Fig. 3 is shown an adjustment of parts ada ted for lighting the pendent lamp that is il ustrated in Figs. 1 and 2, and it will be observed that the resser block 77* is turned so as to press the o tuse angle m thereof and which is furthest from the center of the shaft 5, u on the contact limb f, thus depressing sai limb and establishing electric contact between it and the contact finger h, which will close the circuit between the lamp mentioned and the feeding wires 0, a, while the circuit for the other lamp remains open. I If it is desired to light both lamps simultaneously, the key shaft 5 and presser block '11 thereon are turned as shown in Fig. 4, wherein it will be seen that the acute angles of the presser block that are opposite each other and an equal distance from the axis of the shaft, press upon the contact limbs 01 and f, so as to enforce their contact respectively with the contact fingers e and h, t us completing an electric circuit between the pendent and stand lamps and the feed wires 0, 0.

Obviously the current may be cut off from either or both lamps, by turning the key so as to dispose the presser block as shown respectively in Figs. 3 and 2.

It will be evident that the construction may be slightly changed within the scope ofthe invention, so as to feed the lamps by the wires 6, e, instead of the feed wires 0, c, and support the coupling head 8 on the outer end of a fixed bracket arm that may project from a side wall in a room, the operation being the same in either arrangement of the feed wires.

Having thus described our invention, we claim as new and desire to secure by Letters Patent:

1. In an electric light socket, a hollow body, a hollow branch on one side of the body,a hollow branch on one end of the body, insulated conducting wires in both branches,

electric feeding wires held in the socket body,

a key rockable in the body, and means controlled by said key adapted for making and breaking circuit between the feedingv wires and the conducting wires in either or both branches.

2. In anfelectric. light socket, a hollow metallic body, a hollow metallic branch on one side of the body, a hollow metallic branch on the lower end of said body, an insulating lining in the body and in the branches, conducting wires in the lateral branch, conducting .wires in the de ending branch, two electric feeding wires he d in the body, electric contacts for the wires in the branches, and a rotatable key adapted by adjustment thereof for making or breaking circuit between the feeding wires and the contacts for the wires in either or both branches.

3. In an electric light socket, a mainly cylindrical hollow metallic body, a hollow metallic branch extended laterally from said body, ahollow metallic branch depending from the body, an insulating lining in the body and in the branches, conducting wires in the lateral branch, conducting wires in the depending branch, electric feeding wires entering the upper end of the body, spring contact, limbs extended from the feeding Wires,

contact fingers on certain of the conductor wires, said limbs being disposed near the contact fingers, and a key shaft adapted for rotation in the socket body, and having a rhombus-shaped presser block thereon adapted by partial rotation for pressing the limbs into contact with either or both contact fingers, and also by further rotatable movement breaking the circuit between the feeding wires and either or both conductor wires.

4. In an electric light socket, a hollow socket body, a lateral branch thereon, an extensionhead in said branch, a depending branch on the socket body, an electric lamp having a shank securable in said depending branch, conductor wires extended from an electric stand lamp and held in the extension head, electric feeding wires entering the socket body through the upper end thereof,

two resilient conductor limbs connected withrespective feeding wires, contact fingers on the lamp shank and on the extension head adapted for current transmission, and a key shaft in the socket body rotatable manually, said shaft having a rhombus-shaped presser block eccentrically disposed on the shaft, and adapted by partial rotation for pressing one or both limbs into engagement with respec tive contact fingers and establishing a circuit in one or both lamps, and by further turning movement break circuit between either or both contact fingers for extinguishment of the respective lamps.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

VICTOR E. EXTROM. CHARLES HANCOCK GRUNDY.

-Witnesses A. M. BABCOOK, R. B. WALLIS. 

